I just bought a used 2500 short bed extended cab 4x4. The truck has about 52,000 on it.


It has a bad vibration, enought to make the rear window move when at idle. However, if touch the gas it goes away.


Also, the vibration comes on strong at anything above 55 mph. Brand new tires were just put on less then a week ago so I do not think that is the problem.


Any ideas of what it could be?

Being that it's only present at particular RPMS, it sounds to me like something out of balance. Could be something as simple as a pulley or as complicated as a (gulp) injector. If you don't have smoke and possibly other symptoms, I wouldn't worry about the later...

Ox

Year ?


Allison or ZF6 ?


For help in possible diagnostic help from others ...





Mac

It is an 02 with the Allison. The vibration happens in two wheel drive.Edited by: formula280ss